Sound recording and reproducing



Feb. 9, 1932. A. NARATH 1,844,672

SOUND RECORDING AND REPRODUCING- Filed Jan. 30, 1930 Inventor:

Alba G Namath. by

Hi5 Attorney.

Patented Feb. 9, 1932 to a sound pic UNITED STATES PATENT ALBERT KARATE, OI

omen

BELIZE Gm, ASSIGNOB TO G ELECTRIC OOIPANY,

A CORPORATION 01' You BOUND BEOOBDDIG AND mnonucmo Application fled January 80, 1930, Serial No.

My invention relates to the photographic recordin and reproducing 0 sound. In reproducing from sound records it is sometimes desirable, in order to obtain special effects, to have various sounds or sound events, which may be widely different in character, follow each other and in so following to gradually blend or merge the one into the other. These sound events may have been originally recorded at various times and places and without regard to their being reproduced in the manner mentioned.

It is one object of my invention to provide an improved method of making a photographic record ofa plurality of sound events which when reproduced shall merge the one into the next. Another object of my invention is the provision of the improved record resulting from that method.

My invention will be better understoodfrom the following description taken in connection with the accompan ing drawings, and its sco will be pointe out in the appended clanns.

Referring to the drawings, Fig. 1 is a diagrammatic view of apparatus by means of which the method forming a part of m invention may be carried out, and Fig. 2 shows a portion of the film made in accordance with that method.

In Fig. 1, which shows by we of example apparatus for making a varia le intens ty sound record by the use of a Kerr cell, light rays from the light source 1 pass through the condensing lens 2 and the Kerr cell 3 and finally impin on the moving light sensitive film 4, suitable means, examples of which are well known, bein employed to limit the width of the line 0 .light directed, on the film. In the well'known manner as shown for example in' the British Karolus Patent 235,857, the Kerr cell may be connected through suitable am lifying devices -up device or, ifa r'a-recordin is being made froma reviousl made soun record, the Kerr cell may connected through suitable amplifying devices with the output circuit of a reproducer of the original record. When in the recording process that point on the film 4 is reached at which it is use, and in em; .lebrury is, me.

desired that the sound event then bein recorded shall begin-to fade away an anrays such as diaphragms or light absorbing screens. Iprefer, however, to' inter inthe path of the rays the diaphragm 5 avin an opening therein for the re. s such that w en the diaphragm is moved t e width of l' ht beam directed on the film being ex is varied between a maximum and a minimum. As the diaphragm is thus moved, the record 6 of the first sound event is gradually reduced in width from the full width of the sound track to zero. The film is then stopped and moved back to the point at which the reduction in width of the sound track began. The film is again moved forward while the next sound event is recorded, the diaphragm being now positioned to allow the light to fall on the unexposed portion of the film beginning with a zero width and gradually moving the diaphra to expose the full width of the sound trac thus forming the record 7 of the second sound even. As shown in Fig. 2 these two records 6 and 7 have ta ering portions which overlap each other. en sound reproduction is made from a film such as shown in Fig. 2, the two sound events blend or merge the one into the other, the time required for the mar 'ng being dependent upon the length of t e over: lap ing tapered portions.

'le this method may be used for the original recording of the sound events it is particularly applicable forms when cosymg on a single film sound events origin recorded on separate films but which when reproduced from the copy shall merge the one into the other. The copying may be done in various well known ways such as b contact or optical printers with whi the amount of light reaching thefilm is varied as described when that partof the film is.

the film is gradually direached at which the merging of the sound events is to take place or the copying may merge one into another upon reproduction posing light while one sound event is being reeeera my hand this 6th dgi of Janna 1930.

BERT N BATH.

. which comprises gradually reducing the exrecordedon a certain length of the member and increasing gradually the exposing light while another sound event is'being recorded on the same length of the member 2. The method of photographically recording on a single light-sensitive member a.

plurality-of different sound events so as to merge into one another upon reproduction,

of which events separate records previously U have been made, which comprises gradually reducing the exposing light while the vibrations corresponding to one recordare being recorded on a certain length of the member and graduall increasing the exposing light while the vi rations corresponding to'another record are being recordedfon the sam length of the member.

3. The method of copying on the same length of film sound records of a plurality of different sound events so that they shall merge one into another upon reproduction which comprises exposing said film length to light varied in accordance with one of said records while simultaneously decreasing the amount of light reaching the film, and exposing said length to light varied-in accordance with another of said records while simultaneously increasing the amount of light reaching the film.

4. The method of re-recording on the same length of film two different sound records previously recorded on separate films such that upon reproduction the recorded sounds shall merge the one into the other which:

method comprises exposing said length of film to light varied in accordance with one of said records while steadily decreasing the width of the film being exposed, and exposthe same length of filmto light varied in accordance with another of said records while steadily increasing the width of they film being exposed. p

5. A sound record film havin thereon a plurality of successive variab e intensity records of different sound events adapted upon reproduction to merge the one into the -"next one following, the ad acent ends of said plurality ofsuccessive variable intensity recrecords being tapered an the tapered porhave hereunto set 7 iii? 

